Caster control mechanism for movable trucks and the like



une 30, 1936. J BQWEN 2,046,105

' CASTER CONTROL MECHANISM FOR MOVABLE TRUCKS AND THE LIKE Filed Feb. 25, 19 56 2 Sheets-Sheet l film 65 B0 wen,

A TTORNE Y.

.Fune 30,1936. J BOWEN 2,046,105

GASTER CONTROL MECHANISM FOR MOVABLE TRUCKS AND THE LIKE Filed Feb. 25, 1956 2 Sheets-Sheefi 2 IN VEIY TOR. (foam 6.5" B0 wan, BY

ATTORNEY.

Patented June 30, 1936 UHTED STATES CASTER CONTROL MECHANISM FOR MOV- ABLE TRUCKS AND THE LIKE James Bowen, Manheim, Pa., assignor to Charles Bond, Philadelphia, Pa.

Application February 25, 1936, Serial No. 65,631

13 Claims.

The present invention relates to movable trucks, racks and similar vehicles for transporting articles over short distances, such as about a shop or mill, and is more particularly directed to the provision of novel mechanism for controlling the casters with which such vehicles are customarily provided.

In order that trucks of this general character may be readily moved in any direction at the will of the operator while pushing or pulling them over the floor, they are usually equipped with swivel casters respectively located near the corners of the truck but when all the casters are free to swivel, proper guiding of the truck, especially in close quarters and/ or when it is being pushed rather than pulled by the operator, is extremely difficult due to the failure of the casters to track in or properly adhere to the desired direction of travel.

Attempts have been made to remedy this condition by providing means for looking a plurality of the casters against swivelling, but I have found that if but a single caster at the leading end of the truck is locked so it can rotate only in a plane parallel to the side of the truck, the latter can be very easily and accurately guided from the opposite end, and the present invention is based on this discovery and thus directed to the provision of mechanism which by enabling one caster at either end of the truck to be readily locked against swivelling or unlocked at will, while all the other casters are left free toswivel in the normal manner, enhances the facility with which the truck may be guided while being moved about.

It is therefore a principal object of the invention to provide in a truck or similar vehicle hav-. ing swivel casters, manually operable means for selectively locking either one of a longitudinally aligned pair of the casters against swivelling while simultaneously placing and/ or maintaining the other casters in condition to swivel naturally.

A further object of the invention is to provide mechanism operable from either end of the truck to which it is applied by means of which the op- 45 erator may selectively lock one of the swivel casters at either end thereof so that its wheel is constrained to rotate only in a plane parallel to the side of the truck, and thus in its generally desired direction of travel.

A still further object is the provision in caster locking mechanism of manually operable means which at any time and irrespective of the then position of the caster which it is desired to lock may be set in such manner as to automatically 5.1ock the selected caster upon its subsequently being brought, by movement of the truck or otherwise, into a position such that its wheel lies parallel to the side of the truck.

Another object of the invention is the provision in a truck embodying swivel casters of means 5 manually operable from either end of the truck to selectively lock one of a longitudinally aligned pair of the casters against swivelling and to simultaneously unlock the other caster of said pair in case it has been previously similarly locked.

Additional objects comprehend the provision of locking mechanism capable of performing the aforesaid functions which is of relatively simple design and construction; which can be manipulated with facility by unskilled labor; which is not liable to get out of order or become damaged by rough usage and which can be readily installed on existing trucks or incorporated in new ones at a moderate cost.

Other objects, purposes and advantages of the 20 invention will hereinafter more fully appear or will be understood from the following description of one form of my locking mechanism as illustrated in the accompanying drawings, in which Fig. 1 is a fragmentary side elevation of a truck 25 equipped with the said mechanism showing the latter in intermediate or neutral position in which both casters of the pair controlled thereby are free to swivel in all directions.

Fig. 2 is a similar view showing the locking mechanism in condition to automatically lock one caster upon attainment thereby of a position parallel with the sides of the truck.

Fig. 3 is a similar view showing the same mechanism after the said caster has been brought into parallelism with the sides of the truck and locked against swivelling through the automatic operation of the locking mechanism.

Fig. 4 is a fragmentary horizontal section on the line 4-4 in Fig. 1, 40

Fig. 5 is an enlarged fragmentary detail of a portion of the mechanism shown in Fig. 4,

Fig. 6 is a fragmentary transverse vertical section on the line 66 in Fig. 5.

Fig, 7 is a fragmentary longitudinal vertical section on the line 7- in Fig. 5.

Fig. 8 is an enlarged fragmentary top plan view of the manual operating means and associated parts, and

Fig. 9 is a fragmentary detail corresponding to Fig. 5 but on a reduced scale showing certain of the parts in positions corresponding to Fig. 2.

In the several figures like characters are used to designate the same parts.

More particularly, the truck T which may be of anydesired character is equipped with four with an outwardly and downwardly depending lug', l3- carrying at its lower extremity an integral sleeve Mi, in which isslidably reoeived'a locking dog I5; one endof this dog is'slightly tapered and swivel casters respectively located adjacent its corners; two of these casters 0, C adjacent one side of the truck and which are always free to swivel, may be of any usual type, and therefore require no specific description. 7

The other casters I, I are substantially similar 7 'except'for differences dictated bytheirrespective positions .on the truck'and may varyconsiderably in structural details. Each, howevenessentially comprises a wheel 2 rotatable on an axle 3 can;

ried in a yoke formed by depending lugs 4 in tegralwith a swivel plate 5.. This. platelis rotat -r. 1 ably secured to a" base plate 6, 6, as the case-may be, by a bolt 1 and nut 8, while anti-frictionbearings 9 are desirably interposed between the swivel and base plates to' facilitate the freerswivelling movement of the former underthe-latter;

' r The base plate 6 of the caster l is provided-with,

an extension l2 having'a rectangular openin'gex l tending through it fora purpose'which willhereafter appear, and approXimatelyQOi therefrom,

adapted to enter either of two complementary di-c ametrically opposedznotches lfilintne edge of the swivel plate 5; The 'base platevfi. of the caster l is-provided'wtih a substantially similar but oppositelyeisposed lug 13 sleeve l4 and locking dog i5f adapted toenter the notches.w Hi in the swivelplate f this caster, and alsowith'an exe tension l2 disposed in alignment with the ex-.

tension. l2 of the caster l.

7 Therectangularopenings through these exten sio-ns- IZ 1 and l 2 slidablyl receive "a lock actuating projecting somewhat beyond its ends, and on this.

rod the lockingdogs i5, W are mounted'through' 40? the mediumlof. offset brackets 22; 22a respectively rod 211: extending longitudinally of the truck and integral withthedogs andsecured to the rodin 'longitudinallyspaced relationby set sorews 24; 7 Longitudinal movement-of-the rod is thuseffective to .produce correspondingmovement of the locking dogsintheir sleeves l4, l4and the dogs are a therefore desirablyso positioned on the .rodthat 7 locking dogs are--bo1th disengaged-from the truck;

when thefrod: is: at eitherv limit of its travel. one;

looking dog is fullyenteredin anotch in its adjacentswivel plate and the other is freed entirely 'from engagernent with its adjacent swivel plate,

while when the rod'is -in intermediate position the At the-oppositeendsjofthe truck, substantially identicalmeans-forlongitudinally sliding the ac-,

tuating rodfll areprovided and therefore a description of'those at one end will' suffice equally for those" at the other. Thus'secured near each a end o-f-the lockingrodis a'collar 25-provided with 'an upwardly extending integral fork adapted to loosely receive the lower end of a spring leaf 26 dependingfr'om anpperating lever; 21 whichisic pivotallysupported ona bracket 28mounted on the end wall of the truckand thus adapted for limited oscillatorj movement in aplane parallel to the rod 20. The upper end of'thisle'ver is provided-witha knob 2-9 -or other convenient hand grip andmeans now tobe described are-provided for yieldingly'holding the lever in its neutral 'or:

intermediate and in'theopposedlimit positions of its travel in accordance with-the desires of the operator.

- To this end, a plate 3| is secured toandprojects outwardly from the end-cf th'e truck abovethe bracket; 28- and is provided witha-vertically ex- V tending parti-cylindrical depression or dwellfifl formed on substantially the sameradius as the section of theoperating lever and in substantial vertical alignment with its plane of oscillation and also with generally similar depressions or fdwells 33, 34 oppositely spaced therefrom and H disposed at angles to the vertical corresponding r to radii drawn'from the pivotal axis'an'd omma ing with the limits of movement of rthelever.

The plate 3| is so positioned-that when the lever is engaged therewith between the dwells, appre-r carnbemoved therefrom and along the face of the plate by application of sufficient force to. overcome the resistanceafiordedthereby. V a I 'A,,keeper plate 36 is mounted on plate 3| to prevent the lever from being moved'or bent too far 'ciaole lateral pressure is exerted: thereon and littlev or no such pressure when thelever is in any, of thedwells. Itresults that the leverft'ends to I remain in whichever dwell it'may be engaged but outwardly by careless handlingor'otherwise but' isso positioned as to afford adequate clearance for freermovement of the lever through itsnormal pathof travel. V

As previously-stated, a lever 21 and'associated' parts similar'to those to which reference has just been made are located at eachend of the truck.

In describing the operation of the locking;

mechanism it will be assumed the parts areinitially; in the positions shown in Fig. 1 with both operating levers in'neutral, i. e. in the vertical dwells 32 oftheir plates 3l, and'that the jacenti. e, left hand, operating lever 21 from theidwell 32.1rearwardly to the dwell 33 and the corresponding movement of its spring leaf 26- V in :the opposite direction tends to move'the lock;

actuating rod 2lI-ina like direction,- but if, as is frequently the case, and forpresent purposes willibe assumed, the wheel Z'and bothflof adja cent: notches lfi arenot aligned withthe said 1 pl anedog l5 of caster I cannot enter either ofthese notches but merely engages the periphery "of: the swivel'plate-5 of this caster; The parts arenow in the'positionofFig. 2 and thecas'ter I therefore remains free to swivel until either'off 7 the notches Hit in its swivel plate aligns with the locking dog 15 when the latter immediately enters-the notch dueto the force of the said spring leaf :26 acting" against the ro,d'20 and the resultant movementof the'latter simultaneously causes the operating leverZ'I at the opposite end of :the truck tomoveto and enter its dwell 3 3 corresponding; to the new position of thelocking lnechanism asl a whole-as shown inFig. Of

course, if :at the time the operator initially Imovesl the'leveras above stateda notch It happens to be aligned'with-the locking dog 15* the dog'imJ-i:

mediatelyenters thenotch, and the intermediate positionfiof "the mechanisnras shownsinmFi'gi 2;

is omitted; 77 l y From the foregoing itwill-be readily apparent that if the operatonwishes to lock the'othercaster, I; from the same end of the truck he may readily do so by moving the lever 21 in the opposite directioninto-the dwellj34," preferably hold-'- ing'ituntil the-dog I I 5 enters a slotl6, ifit does not do'soimmediately, while, in a corresponding manner either caster may be locked from the opposite end of the truck by means of the lever adjacent that end, and either caster likewise unlocked by suitable reverse movement of either lever in accordance with the will of the operator.

It results that a truck furnished with casters and control means therefor constructed in accordance with my invention may be used as an ordinary swivel truck when the caster locking mechanism is in neutral position and that when desired one caster, which will usually be a front caster corresponding to the direction of travel of the truck, may readily be releasably locked against swivelling and its wheel maintained in a plane parallel to the sides of the truck so as to cause it to track in, that is adhere to, the desired path of movement of the latter as determined by the operator and may be as readily unlocked and again allowed to swivel.

Consequently when the truck is to be moved into a narrow space, as when a baker's rack or the like is placed in a proofing oven, in which the clearance about the sides of the truck or rack is usually quite narrow, the operator may readily guide the truck from the rear while moving it into the oven with a front caster locked against swivelling and then, when the truck is to be withdrawn, may unlock that caster and lock one at the opposite and now front end prior to withdrawing the truck from the oven without being required to go into the oven beyond the outer end of the truck at any time, since as above pointed out, the locking of a front caster facilitates movement of the truck along a substantially rectilinear path without occurrence of the frequent erratic departures therefrom which usually take place when all the casters are free to swivel.

Moreover, since the mechanism is so arranged as to render simultaneous locking of both casters impossible, no matter how carelessly it is operated, no more than one caster can ever be locked at the same time and the truck is thus capable of being moved substantially in any direction at all times although when it is desired to move it laterally it is preferable that all the casters be free to swivel as if one of them is locked it may be damaged or may damage the fioor. However, as either caster can be locked and unlocked from either end of the truck by a simple movement of either operating lever, the truck may very readily be placed in the preferred condition for either lateral or longitudinal movement.

While I have herein described one embodiment of my invention with considerable particularity, and have referred to certain ways of utilizing a locking mechanism constructed in accordance therewith, it will be understood I do not thereby desire or intend to limit or confine myself thereto in any way as changes and modifications in the form, structure and arrangement of the several parts and their mode of operation will readily occur to those skilled in the art and may be made if desired without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus described my invention, I claim and desire to protect by Letters Patent of the United States:

1. In combination with a truck of the class described, a pair of swivel casters having notched swivel plates, a longitudinally slidable rod, looking dogs carried by the rod respectively adapted to enter the notches in the plates and means for sliding the rod comprising pivoted actuating levers respectively supported adjacent the ends of the truck and yielding means connecting each lever with the adjacent end of the rod whereby when either lever is moved about its pivot in either direction the rod is urged to move in a corresponding direction to thereby move the dogs oppositely with respect to their adjacent swivel plates.

2. In combination with a truck of the class described, a pair of swivel casters, an actuating rod slidably supported therefrom, means carried by the rod respectively adapted to releasably lock the casters against swivelling and means for actuating the rod to selectively lock one caster or the other or to permit both casters to swivel comprising collars respectively secured to the rod adjacent its ends, pivoted actuating levers respectively disposed adjacent the ends of the truck, springs flexible in the direction of movement of the rod respectively forming yielding connections between the levers and collars and means engaging each lever respectively adapted to yieldingly maintain it in predetermined pivotal relations to the truck.

3. In caster locking mechanism for a truck of the class described, a longitudinally slidable actuating rod. disposed beneath the truck and projecting beyond the ends thereof, manually movable operating levers pivotally supported adjacent the ends of the truck, a leaf spring interconnecting each lever with the adjacent end of said rod and yieldable longitudinally of the rod and a plate carried by the truck adjacent each lever b projecting into the plane of normal pivotal movement thereof and having a plurality of lever receiving grooves disposed in substantial coincidence with said plane and respectively adapted when the lever is entered therein to yieldingly of integral projections respectively affording elongated apertures having parallel axes, a notched swivel plate pivotally carried by the base plate, a caster wheel rotatably supported thereon, a dog slidable in the aperture in one of the projections adapted to enter a notch in the swivel plate to thereby restrain its pivotal movement with respect to the base plate, a rod slidable in the aperture in the other projection interconnected with and operable to actuate said dog and means for sliding the rod. 5. In combination with a truck of the class described, a pair of casters each comprising a base plate secured to the truck, a notched swivel plate pivotally secured to the base plate, a rotatable caster wheel carried by the swivel plate and means supported from the base plate operable to enter a notch in the swivel plate to lock it against rotation, a longitudinally slidable rod extending adjacent the casters and interconnected with the notch entering means whereby by moving the rod in either direction one of said means may be caused to enter a notch in the swivel plate of one caster if said notch be aligned with said means, and the other of said means retracted from the swivel plate of the other caster, and manually operable means respectively disposed adjacent the ends of the truck for moving the rod in opposite directions.

6. In caster locking mechanism of the class described, a. pair of swivel casters, a longitudinally V slidable rod extending adjacent thereto, means carried 'by'the rod selectively operable to releasably lock either caster against swivelling, manually operable levers adapted forpivotal move--' :ment substantially in the plane of, the rod 're-' spectively disposed adjacent each end thereof,

lever in correspondingdirections in response'to V movements of the rod. 7

7. In combination with a truck bf the class described, apair of longitudinally aligned swivel casters having notched swivel plates, an actu- 'ating rod extending longitudinally, of the truck,

locking dogs carried by the rod respectively adapted to enter a'notch in one of said plates; a pivoted operating lever disposedadjacent eachend of the rod having a spring connection therewith and a plate associated with each lever having a plurality of grooves respectively corresponding to in;-

termediate and limit lever positions, the plate serving to deflect the lever'from its normal plane of oscillation when it is moved frormone of said grooves to another:

a. In combination with a'truck of the class de 'scribed' a pair of longitudinally aligned swivel casters, an actuating rod extending longitudinally of the truck and axially movable with respect thereto, means carried thereby adapted to selectively releasably lock either casteragainst swivele ling, pivoted operating levers respectively disposed adjacent the ends of the rod operable to move --the rod-axially to actuate said locking'mcans, meansyieldingly connecting the levers with the V rod, and means engaging each levercadapted to tudinally slidable rod; a' pivoted operating lever yieldingiy rest-rain its pivotal movement. 7 j 9. In truck caster locking mechanism, a longidisposed adjacent each end of the rod; a leaf spring extending from one end of each lever and J loosely interconnected with the adjacent end of the rod, and means respectively engaging the levers adjacent their other ends adapted to yieldingly resist movement of the levers abc-ut their pivots. a

10. 'In truck caster locking mechanism, ap'air of swivel casters, a siidab-le rod, means disposed in longitudinally spaced' relation on the rod ree -r sp e-ctively adapted when the rod is in the! limit positions of its travel to lock one caster against swivelling and leave the other caster free to swivel, a lever pivoted adjacent each end of the rod, a fork on the rod adjacent each lever, and

a leaf spring extending irom'one'end of each 7 i 12-; In combination with a lever into said fork plane of oscillation of the lever.

and adapted totflex inthe' 1 1. 'In truck caster, locking mechanism,l a. pair '7 of swivel casters, alslidable rod, means disposed;

in longitudinaliy spaced relation on the rodrespectively adaptedwhen the rod is in the 7 positions of its travelto. lock onefvcasteri against swivelling and leave the other caster free to swivel, alever pivoted adjacent each end of the; V

rod; a fork on the rod adjacent eachlever, a

leaf spring extending from. one end of each'lever intosaidfork and adapted to flex infthe: plane; of oscillation of the lever, and meanstending to yieldingly restrain the. levers frond oscillation.

about their respective pivots.

described, a pair of longitudinally aligned swivel casters each having a swivel piate with a notch in its periphery, an actuating rod extending longitudinally of the truck, locking dogs carried by the rod adjacent each caster and respectively p 7 V v 15' truck of the class adapted to enter a' notch inthe swivel plate" 7 thereof to thereby lock it against rotation; a pivoted operating lever disposed adjacent'each end of the truck,and a leaf spring depending'irom 'each'lever adapted to flex in its plane of oscillation, the free end ofrthe spring'forming a loose connection the adjacent end of the rod,

whereby moi -nent of either lever to either'of its liinit positionsis operative'torflex its adja cent spring and thereby apply spring pressure to the rod tending to move it in a direction to cause one of the dogs to automatically enter a notch inithe adjacent'swivel plate whenever the latter comes into alignment with thedog.

13. in combination with a truck of the class described, apair of longitudinally aligned swivel v :7

casters each having a'swivel platerwithfa notch in its periphery, an actuating rod extending longitud inally of the'tru'ck, locking dogs carried by the rod adjacent each caster and ;,respectively' adapted to enter a notch in the's'wivel plate thereof to thereby lock it against rotation, at pivoted operating le-ver disposed adjacent each'end ofp-the'truckQand a leaf spring depending from 7 each lever adaptedto flex initsplane of oscillation, the free end of the springionning a loose whereby movement of either lever to either of its limit positions is operative through itsiad jacent spring to apply spring pressure to the rod, tending to move it in a direction tocause one connection with the adjacent end of "the rod, 7

ofthe dogs to engage the swivel plate of one of =the castersif its periphery is' then aligned with said dog and tocause the dog to automatically enter a. notch in said plate whenever it thereafter brought into alignment therewith.

JAMES BOWEN; 

